1. Field of the Invention
The present invention relates-to a cooling device for an electronic component such as a rectifier diode by which heat is generated in the operation.
2. Description of the Prior Art
A conventional heat sink for cooling an electronic component such as a rectifier diode by which heat is generated in the operation is disclosed, for example, in Japanese Utility Model Publication No. Sho. 55-75198.
FIG. 4 is a view showing the heat sink disclosed in the above utility model publication. In this heat sink, an electronic component 13 such as a rectifier diode by which heat is generated is fixed to one side of an attaching member 11 with screws 15, and a plurality of radiating plates 17 are fixed to the other side of the attaching member 11.
Undulated radiating fins 19 are arranged among the radiating plates 17.
In this heat sink, the heat generated by the electronic component 13 is transmitted to the undulated radiating fins 19 via an attaching member 11 and the radiating plates 17. Thus transmitted heat is radiated from the undulated radiating fins 19 to the atmosphere. Therefore, the electronic component 13 can be effectively cooled.
However, according to the above conventional heat sink, the electronic component 13 is cooled by natural radiation conducted by the radiating plates 17 and the undulated radiating fins 19. Accordingly, the above conventional heat sink is disadvantageous in that the cooling efficiency is low.
When the capacity of the electronic component 13 is increased, a quantity of heat generated by the electric component 13 is also increased. Therefore, the length of the radiating plates 17 is necessarily increased. However, when the radiating plates 17 are, longer the heat transmission efficiency of the radiating plates 17 is decreased in the heat transmission from the radiating plates 17 to the heat radiating fins 19. This decrease in heat transmission is originated from the heat conductivity of the radiating plate 17. Therefore, even if the number of the radiating fins 19 is increased so as to increase the radiating area, the cooling capacity is not increased. In other words, it is difficult to increase a quantity of heat radiated from the radiating fins, so that the electronic component 13 can not be cooled well.